1. Measure of extraction efficiency.

2. In mining, the percentage of metal derived from an ore, or coal from a coal seam, etc.

3. In petroleum geology, the percentage of the in situ oil that is recoverable. Between 20% and 40% is common for primary recovery techniques, but enhanced recovery by use of water injection, detergents to reduce viscosity, etc., may increase the recovery factor to 75%. Recovery factors for natural gas can be as high as 90%.